feat(debug): add preview toggles and auto-close ads

- 기록/통계 탭에 디버그 토글 배너 추가 및 테스트 데이터 주입 로직 상태화\n- 리스트 공유 화면에 디버그 프리뷰 토글, 광고 관문, 디버그 전송 흐름 반영\n- 모의 전면 광고는 대기 시간 종료 시 자동 완료되도록 변경\n- AGENTS.md에 코멘트는 한국어로 작성 규칙 명시\n\n테스트: flutter analyze; flutter test

lib/presentation/pages/calendar/calendar_screen.dart

@@ -1,3 +1,4 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:table_calendar/table_calendar.dart';
@@ -6,10 +7,12 @@ import '../../../core/constants/app_typography.dart';
 import '../../../domain/entities/recommendation_record.dart';
 import '../../../domain/entities/visit_record.dart';
 import '../../providers/recommendation_provider.dart';
+import '../../providers/debug_test_data_provider.dart';
 import '../../providers/visit_provider.dart';
 import 'widgets/visit_record_card.dart';
 import 'widgets/recommendation_record_card.dart';
 import 'widgets/visit_statistics.dart';
+import 'widgets/debug_test_data_banner.dart';
 
 class CalendarScreen extends ConsumerStatefulWidget {
   const CalendarScreen({super.key});
@@ -32,6 +35,11 @@ class _CalendarScreenState extends ConsumerState<CalendarScreen>
     _selectedDay = DateTime.now();
     _focusedDay = DateTime.now();
     _tabController = TabController(length: 2, vsync: this);
+    if (kDebugMode) {
+      Future.microtask(
+        () => ref.read(debugTestDataNotifierProvider.notifier).initialize(),
+      );
+    }
   }
 
   @override
@@ -100,6 +108,10 @@ class _CalendarScreenState extends ConsumerState<CalendarScreen>
 
         return Column(
           children: [
+            if (kDebugMode)
+              const DebugTestDataBanner(
+                margin: EdgeInsets.fromLTRB(16, 16, 16, 8),
+              ),
             // 캘린더
             Card(
               margin: const EdgeInsets.all(16),

lib/presentation/pages/calendar/widgets/debug_test_data_banner.dart

@@ -0,0 +1,92 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:lunchpick/core/constants/app_colors.dart';
+import 'package:lunchpick/core/constants/app_typography.dart';
+import 'package:lunchpick/presentation/providers/debug_test_data_provider.dart';
+
+class DebugTestDataBanner extends ConsumerWidget {
+  final EdgeInsetsGeometry? margin;
+
+  const DebugTestDataBanner({super.key, this.margin});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    if (!kDebugMode) {
+      return const SizedBox.shrink();
+    }
+
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final state = ref.watch(debugTestDataNotifierProvider);
+    final notifier = ref.read(debugTestDataNotifierProvider.notifier);
+
+    return Card(
+      margin: margin ?? const EdgeInsets.all(16),
+      color: isDark ? AppColors.darkSurface : AppColors.lightSurface,
+      elevation: 1,
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+      child: Padding(
+        padding: const EdgeInsets.all(12),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Row(
+              children: [
+                const Icon(
+                  Icons.science_outlined,
+                  color: AppColors.lightPrimary,
+                  size: 20,
+                ),
+                const SizedBox(width: 8),
+                Text(
+                  '테스트 데이터 미리보기',
+                  style: AppTypography.body1(
+                    isDark,
+                  ).copyWith(fontWeight: FontWeight.w600),
+                ),
+                const Spacer(),
+                if (state.isProcessing)
+                  const SizedBox(
+                    width: 20,
+                    height: 20,
+                    child: CircularProgressIndicator(strokeWidth: 2),
+                  ),
+                const SizedBox(width: 8),
+                Switch.adaptive(
+                  value: state.isEnabled,
+                  onChanged: state.isProcessing
+                      ? null
+                      : (value) async {
+                          if (value) {
+                            await notifier.enableTestData();
+                          } else {
+                            await notifier.disableTestData();
+                          }
+                        },
+                  activeColor: AppColors.lightPrimary,
+                ),
+              ],
+            ),
+            const SizedBox(height: 8),
+            Text(
+              state.isEnabled
+                  ? '디버그 빌드에서만 적용됩니다. 기록/통계 UI를 테스트용 데이터로 확인하세요.'
+                  : '디버그 빌드에서만 사용 가능합니다. 스위치를 켜면 추천·방문 기록이 자동으로 채워집니다.',
+              style: AppTypography.caption(isDark),
+            ),
+            if (state.errorMessage != null) ...[
+              const SizedBox(height: 6),
+              Text(
+                state.errorMessage!,
+                style: AppTypography.caption(isDark).copyWith(
+                  color: AppColors.lightError,
+                  fontWeight: FontWeight.w600,
+                ),
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+}

lib/presentation/pages/calendar/widgets/visit_statistics.dart

@@ -1,9 +1,11 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:lunchpick/core/constants/app_colors.dart';
 import 'package:lunchpick/core/constants/app_typography.dart';
 import 'package:lunchpick/presentation/providers/visit_provider.dart';
 import 'package:lunchpick/presentation/providers/restaurant_provider.dart';
+import 'package:lunchpick/presentation/pages/calendar/widgets/debug_test_data_banner.dart';
 
 class VisitStatistics extends ConsumerWidget {
   final DateTime selectedMonth;
@@ -32,6 +34,10 @@ class VisitStatistics extends ConsumerWidget {
       padding: const EdgeInsets.all(16),
       child: Column(
         children: [
+          if (kDebugMode) ...[
+            const DebugTestDataBanner(margin: EdgeInsets.zero),
+            const SizedBox(height: 12),
+          ],
           // 이번 달 통계
           _buildMonthlyStats(monthlyStatsAsync, isDark),
           const SizedBox(height: 16),
@@ -130,7 +136,7 @@ class VisitStatistics extends ConsumerWidget {
                     : stats.values.reduce((a, b) => a > b ? a : b);
 
                 return SizedBox(
-                  height: 120,
+                  height: 140,
                   child: Row(
                     mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                     crossAxisAlignment: CrossAxisAlignment.end,